In a manufacturing process of a crystal display panel, many steps relate to transferring and supplying of liquid material, for example, photoresist coating and developer spraying. Thus, transferring and supplying of liquid material are essential steps in a manufacturing process of a crystal display panel.
FIG. 1 is a schematic diagram showing a photoresist supplying structure of a photoresist coating equipment according to prior art. The photoresist supplying structure includes a tank 1 for storing photoresist. Usually, the tank 1 is made of polyethylene (PE) material. Two communication pipes are provided on an end cover of the tank 1, and are inserted into the tank 1. A first pipe 2 of the two communication pipes is a stainless steel pipe, and extends to a position above a bottom of the tank 1, and transfers the photoresist to outside. A second pipe 3 of the two communication pipes is a gas inlet pipe, and injects pressured gas having a predetermined pressure to the inside portion of the tank 1. During a photoresist coating, based on a pressure difference principle, the second pipe 3 injects gas to the inside portion of the tank 1 to make an inside pressure of the tank 1 higher than an outside pressure, so that the photoresist stored in the tank 1 is output through the first pipe 2 and is provided to the photoresist coating equipment.
However, in an actual photoresist coating technology, when the second pipe 3 injects gas into the tank 1, the pressure of the gas causes a deformation of the tank. When the deformation of the tank 1 occurs, a deformation amount in a length is greater than a deformation amount in a width. Thus, as shown in FIG. 2, a distance between the first pipe 2 and the bottom of the tank 1 increases. In this structure, the photoresist remained at a bottom portion of the tank 1 cannot be absorbed by the first pipe 2 and cannot be used, and this structure causes a waste of the material.